Hydrophilic interaction chromatography and evaporative light scattering detection for the determination of polar analytes in Belgian endive

- Sugars, amino acids, sesquiterpenes and salts were detected in Belgian endive.
- A fast method was developed in HILIC-HPLC-ELSD, running in under seven minutes.
- Absolute quantification was obtained of sugars, glutamine, potassium and chloride.
- Belgian endive varieties differ in the content of polar analytes.

Belgian endive (Cichorium intybus L. var. foliosum Hegi), a popular produce in northern Europe, has been thoroughly studied in regard to its bitter sesquiterpene lactones content. Much less is known about on its sweetness and crunchiness, which are typically linked to the content of polar compounds such as sugars, organic acids and salts. Through HILIC-HPLC-MS, it was shown that simple sugars, amino acids, and potassium chloride are abundant in Belgian endive extracts. Subsequently, a HILIC-HPLC-ELSD method for the analysis of such compounds with run times below six minutes was developed. Recoveries varied between 80 and 110% and an average reproducibility was 7.5 RSD%. Finally, the method was applied to the study of three difference Belgian endive varieties. Takine, a variety known for its sweet taste, was found to contain significantly higher levels of fructose, and lower levels of potassium and glutamine.